Digging deeper can be done in the following ways
1. What is the so what? You have arrived at the answer and solved the problem - what is the implication of it? Does it impact any previous findings?
2. What can you consider that is not immediately obvious? Do the charts convey a pattern you could have missed? Especially look for continuity/connection across questions
3. Go one step further in your conclusions. For example if 2 players in a market have the same profit maybe this is a perfectly competitive market and not a good one to enter etc.
All the best for your final round!